Fibre based panels with a decorative wear resistance surface

ABSTRACT

A method to produce building panels is disclosed which method includes the step of applying a layer ( 5 ) comprising a mix of fibres ( 14 ), binder ( 12 ), and wear resistant particles ( 12 ) on a carrier ( 6 ), pressing the layer ( 5 ) with an embossed matrix ( 2   a ,  2   b ) and providing embossed portions ( 4 ) and filling the embossed portions with decorative a substance ( 3 ).

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional Application No. 61/295,514, filed on Jan. 15, 2010, and claims the benefit of Swedish

Application No. 1050039-5, filed on Jan. 15, 2010. The entire contents of each of U.S. Provisional Application No. 61/295,514 and Swedish Application No. 1050039-5 are hereby incorporated herein by reference.

TECHNICAL FIELD

The disclosure generally relates to the field of fibre-based panels with wear resistant surfaces for building panels, preferably floor panels. The disclosure relates to building panels with such wear resistance surface and particularly to production methods to produce such panels.

FIELD OF APPLICATION

The present disclosure is particularly suitable for use in floating floors, which are formed of floor panels comprising a core and a decorative wear resistant solid surface layer comprising fibres, binders and wear resistant particles as described in WO 2009/065769. The following description of technique, problems of known systems and objects and features of the invention will therefore, as a non-restrictive example, be aimed above all at this field of application and in particular at floorings which are similar to traditional floating wood fibre based laminate floorings. The disclosure does not exclude floors that are glued down to a sub floor.

It should be emphasized that the disclosure can be used to produce a complete panel or a separate surface layer, which is for example applied to a core in order to form a panel. The disclosure can also be used in applications as for example wall panels, ceilings, and furniture components and similar.

BACKGROUND

Wood fibre based direct pressed laminated flooring usually comprises a core of a 6-12 mm fibre board, a 0.2 mm thick upper decorative surface layer of laminate and a 0.1-0.2 mm thick lower balancing layer of laminate, plastic, paper or like material.

The surface layer of a laminate floor is characterized in that the decorative and wear properties are generally obtained with two separate layers one over the other.

The printed decorative paper and the overlay are impregnated with melamine resin and laminated to a wood fibre based core under heat and pressure.

Recently new “paper free” floor types have been developed with solid surfaces comprising a substantially homogenous mix of fibres, binders and wear resistant particles.

The wear resistant particles are preferably aluminium oxide particles, the binders are preferably thermosetting resins such as amino resins and the fibres are preferably wood based. Other suitable wear resistant materials are for example silica or silicon carbide. In most applications decorative particles such as for example colour pigments are included in the homogenous mix. In general all these materials are preferably applied in dry form as a mixed powder on a HDF core and cured under heat and pressure to a 0.1-1.0 mm solid layer.

Several advantages over known technology and especially over conventional laminate floorings can be obtained:

-   -   The wear resistant surface layer, which is a homogonous mix, can         be made much thicker and a wear resistance is achieved, which is         considerably higher.     -   New and very advanced decorative effects can be obtained with         deep embossing and by separate decorative materials, which can         be incorporated into the homogenous surface layer and         coordinated with the embossing.     -   An increased impact resistance can be reached with a homogenous         surface layer, which is thicker and has a higher density.     -   The homogenous surface layer can comprise particles that have a         positive impact on sound and moisture properties.     -   Production costs can be reduced since low cost and even recycled         materials can be used and several production steps can be         eliminated.

Powder technology is very suitable to produce a decorative surface layer, which is a copy of stone and ceramics. It is however more difficult to create designs such as for example wood decors.

Powder based floors could reach a much higher market share if advanced designs similar to for example wood floorings could be made in a cost efficient way as described in this application.

Definition of Some Terms

In the following text, the visible surface of the installed floor panel is called “front side”, while the opposite side of the floor panel, facing the sub floor, is called “rear side”. By “surface layer” are meant all layers which give the panel its decorative properties and its wear resistance and which are applied to the core closest to the front side covering preferably the entire front side of the floorboard. By “decorative surface layer” is meant a layer, which is mainly intended to give the floor its decorative appearance. “Wear layer” relates to a layer, which is mainly adapted to improve the durability of the front side.

By “horizontal plane” is meant a plane, which extends parallel to the outer part of the surface layer. By “horizontally” is meant parallel to the horizontal plane and by “vertically” is meant perpendicularly to the horizontal plane. By “up” is meant towards the front side and by “down” towards the rear side.

Known Technique and Problems Thereof

FIG. 1 shows a known embodiment of the new “paper free” floor type with a solid surface 5 comprising a mixture of fibres, preferably wood fibres 14, small hard wear resistant particles 12, 12′ and a binder 19. The wood fibres are generally unrefined and of the same type as used in HDF and particleboard. They comprise natural resins such as lignin. The wear resistant particles (12,12′) are preferably aluminium oxide particles. The surface layer comprises preferably also colour pigments 15 or other decorative materials or chemicals.

A preferable binder is melamine or urea formaldehyde resin. Any other binder, preferably synthetic thermosetting resins, could be used. The solid layer 5 is generally applied in dry powder form on a wood based core 6, such as for example HDF, and cured under heat and pressure. The binder 19 penetrates into the upper part of the core 34 and connects the solid surface layer to the core.

An advanced decorative pattern can be applied in line on a scattered or pre-pressed surface with for example an ink jet digital device, which allows the ink to penetrate into the powder. The major disadvantage is that printing is made before pressing and special positioning is required if the printed pattern should be coordinated with the embossed structure created by the press plate

An integrated pressing and design “stamp” method can be used whereby an embossed pressure matrix comprising protrusions, which are covered with a selected paint, for example with a rubber roller that applies the paint only on the protrusions and not on the matrix parts located at lower portions between the protrusions. During pressing, it is possible to apply the selected paint only in the sections of the surface that are pressed below the top parts of the surface layer and a perfect coordinated design and structure could be obtained. The main disadvantage is that ink has to be applied on the hot press plate and that a roller must be inserted into the press. This will have a negative impact on the pressing capacity.

OBJECTS AND SUMMARY

An overall objective of embodiments of the disclosure is to provide a building panel, preferably a floor panel with a solid surface, which has better design properties and/or cost structure than the known building panels.

A first objective of embodiments of the disclosure is to provide a solid laminate panel, preferably a floor panel, with an advanced surface design preferably coordinated with an embossed structure, which can be combined with a high wear resistance.

A second objective of embodiments of the disclosure is to provide a cost efficient method to produce advanced surface design,

According to a first aspect of the disclosure a production method is provided comprising the steps of:

-   -   Applying a layer comprising a mix of fibres, binder and wear         resistant particles, preferably aluminium oxide particles, on a         carrier.     -   Providing embossed portions on the layer by pressing the mix         with an embossed matrix.     -   Filling the embossed portions with decorative material.

The pressing can be made as a pre pressing before the main pressing which cures the surface under heat and pressure. The decorative material is in this alternative applied after the pre pressing but before the main pressing. The advantage is that even a glossy flat surface can be made with the decorative material incorporated into the solid laminate surface. The pre pressed surface could of course also be pressed with an embossed matrix in the main pressing step.

The decorative material can also be applied after the main pressing step. In such a case an embossed structure can be maintained.

The two principles can be combined and several pressing steps can be made for example pre pressing, main pressing and secondary pressing and decorative materials can be applied before and/or during and/or after the main and/or secondary pressing steps.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will in the following be described in connection to preferred embodiments and in greater detail with reference to the appended exemplary drawings, wherein

FIG. 1 illustrates a known solid laminate surface;

FIGS. 2 a-d illustrate a method to form a decorative surface;

FIGS. 3 a-c illustrate an alternative method to form a decorative surface;

DETAILED DESCRIPTION OF EMBODIMENTS

FIGS. 2 a-2 d show a production method to produce a decorative surface 5 in order to form a building panel 1 according to the invention. A mix 5 of fibres, binder, and wear resistant particles is applied on a carrier 6, which preferably is a wood based core as shown in FIG. 2 a. The mix is preferably applied with scattering equipment in dry form and could preferably comprise a decorative substance, for example colour pigments that provide a basic colour.

An embossed portion 4 is formed by pre pressing in the uncured surface mix 5 with a matrix 2 a as shown in FIG. 2 b. A decorative substance 3 is applied in the embossed portion (FIG. 2 c) and the surface is pressed in a main pressing step where the mix 5 is cured to its final form, as shown in FIG. 2 d.

The decorative substance can be applied in many ways for example by applications where scattering is combined with vibration and where the decorative substance is automatically positioned in the embossed portions. The decorative substance can also be applied as a layer that partly or completely covers the surface after excess material outside the embossed portions is removed for example mechanically or with compressed air and similar methods.

Suitable decorative substances are colour pigments, paint, ink, pastes and pre coloured fibres.

The decorative substance comprises preferably also wear resistant particles and binders.

FIGS. 3 a-3 c show an alternative method according to the invention. The surface 5 is applied as powder (FIG. 3 a) and pressed in a main pressing step such that embossed portions 4 are formed in the cured surface.

The embossed portions are filled with a decorative substance that can fill the whole embossed portion or only parts such that a perfect coordination between the design and embossing is obtained.

The decorative material can be cured with various known methods after or during the application into the embossed portions. Further pressing steps are not excluded.

Using a paper based overlay or an overlay which is applied in wet or dry form and which comprised wear resistant particles, is not excluded and this could increase the wear resistance. 

1. A method of manufacturing a building panel comprising the steps of: applying a layer comprising a mix of fibres, binder, and wear resistant particles on a carrier; pressing the layer with an embossed matrix and providing embossed portions; and filling the embossed portions with a decorative substance.
 2. The method as claimed in claim 1, wherein the panel is a floor panel.
 3. The method as claimed in claim 1, the step further comprising an additional pressing that is made after filling of the embossed portions.
 4. The method as claimed in claim 1, wherein the carrier is a HDF board.
 5. The method as claimed in claim 1, wherein the decorative substance comprises wear resistant particles and a binder.
 6. The method as claimed in claim 1, wherein the decorative substance comprises colour pigments and wood fibres.
 7. The method as claimed in claim 2, wherein the carrier is a HDF board.
 8. The method as claimed in claim 3, wherein the carrier is a HDF board.
 9. The method as claimed in claim 5, wherein the wear resistant particles of the decorative substance are aluminium oxide particles.
 10. The method as claimed in claim 2, where the decorative substance comprises wear resistant particles.
 11. The method as claimed in claim 10, wherein the wear resistant particles of the decorative substance are aluminium oxide particles.
 12. The method as claimed in claim 3, where the decorative substance comprises wear resistant particles.
 13. The method as claimed in claim 12, wherein the wear resistant particles of the decorative substance are aluminium oxide particles.
 14. The method as claimed in claim 4, where the decorative substance comprises wear resistant particles.
 15. The method as claimed in claim 14, wherein the wear resistant particles of the decorative substance are aluminium oxide particles.
 16. The method as claimed in claim 1, wherein the wear resistant particles are aluminium oxide particles. 